For example, U.S. Pat. No. 4,729,564 (hereinafter referred to as a first prior art document), Japanese Patent Laid Open Gazette No. 11183/1990 (hereinafter referred to as a second prior art document), and Japanese Patent Laid-Open Gazette No. 23592/1990 (hereinafter referred to as a third prior art document) disclose a game set playing various games on the basis of bar code data read from a bar code card. However, the first to third prior art documents utilize the bar code data read from the bar code card by a bar code reader without any modification and fail to disclose a technique for removing various types of noise included in the bar code data. Therefore, erroneous data is liable to be inputted to the game set by the bar code data including the noise. Particularly in the field of the game set, lower cost is required. Accordingly, it is impossible to use, as the bar code reader, a high-cost and high-precision one. Consequently, it is highly possible that noise is included in the bar code data read by such a bar code reader.
On the other hand, such a game set that a battle game can be played using a bar code card has been commercially available and an application for the game set has been filed in recent years (for example, a trade name "Bar Code Battler" made by Epoque Co., Ltd.; Japanese Patent Laid-Open Gazette No. 193, 074/1981). This conventional bar code game set (hereinafter referred to as a fourth prior art document) is so constructed that a battle game can be played using a bar code card produced by a player himself or herself of the game. Specifically, the player uses a bar code card attached or uses an original bar code card to which a bar code attached to a commercially available commodity is affixed and causes the game set to read the bar code card to play the battle game. In the bar code card produced by the player himself or herself, however, the bar code is generally inferior in state in many cases. Accordingly, it is very highly possible that noise is included in the bar code data read by the bar code reader. For example, when a bar code cut from a package of a commodity is bonded to a card and used, dust is liable to adhere to the bar code by adhesives squeezed from the adhesive surface. In this case, the dust adhering to the bar code is liable to be erroneously recognized as a part of a black or white bar included in the bar code. In addition, when the bar code attached to the commodity is damaged from the beginning, a read error occurs in a damaged portion. Furthermore, when the bar code attached to the commodity is copied by a copying machine and used, the shape of each of the bars in the bar code is deformed by distortion of an optical system in the copying machine. Particularly when copying of the bar code is repeated many times, the degree of deformation of each of the bars is increased. In this case, the width of each of the bars is not normally read, thereby causing a read error. However, the above described game set in the forth prior art document utilizes the bar code data read from the bar code card without any modification and fails to disclose a technique related to signal processing for removing noise included in the bar code data, similarly to the above described first to third prior art documents. Therefore, the above described game set in the fourth prior art document has the disadvantage in that a read error frequently occurs, whereby the interest in the game is lost.
Therefore, an object of the present invention is to provide an improved bar code reader capable of reliably detecting various types of noise included in bar code data and improving the reading precision of a bar code even if a relatively simple and low-cost optical reader is used.
Another object of the present invention is to provide an improved bar code reader capable of reliably detecting noise in bar code data and nullifying the same.
Still another object of the present invention is to provide an improved bar code reader capable of correcting distortion of the width of each of bars included in a bar code.
A further object of the present invention is to provide an improved bar code reader capable of correcting a read error in a bar code due to the change in the speed of movement of a bar code record medium.
A still further object of the present invention is to provide an improved game set capable of reliably detecting and nullifying various types of noise included in bar code data inputted and using the inputted bar code data for processing for a game.